Motor and compressor

ABSTRACT

A motor includes a rotor and a stator, the stator having a stator core and an electrical insulator assembly at each end of the stator core. The electrical insulator assemblies each have an outer wall part extending in a circumferential direction and facing a yoke of the stator core and a plurality of extending parts extending radially inward from the outer wall part and facing teeth of the stator core. The outer wall part has a radial thickness and includes a plurality of radial notches for guiding extensions of the stator winding between an inner peripheral surface and an outer peripheral surface of the outer wall part. The outer peripheral surface of the outer wall part adjacent to the notches is configured such that the radial thickness of the outer wall part gradually decreases toward the notch along a circumferential direction of the yoke.

CROSS-REFERENCE

This application claims priority to Japanese patent application no.2021-213546 filed on Dec. 27, 2021, the contents of which are fullyincorporated herein by reference.

TECHNICAL FIELD

The present disclosure generally relates to a motor and a compressorusing the same as a driving source.

BACKGROUND ART

In so-called eco-friendly cars such as hybrid vehicles (HV), electricvehicles (EV) and fuel cell vehicles (FCV), a compressor (which may bereferred to as an “electric compressor”) in which a compressionmechanism is driven by a motor is used as a compressor for an airconditioner.

Recently, along with an increase of the power supply voltage ofvehicles, motors of high-pressure specifications are also desired to beused in electric compressors. For example, a technique for ensuring aminimum electrical insulation distance between parts, or a technique forpreventing contact between parts is desired to be developed.

A motor (a so-called “concentrated winding motor”) having a stator (aso-called “concentrated winding stator”) in which electrical insulationassemblies are arranged on stator core end surfaces on both sides of thestator core in an axial direction, respectively, and in which a leadwire forming a stator winding is wound around a tooth of the statorcore, has been used as a motor for driving a compression mechanism. Thelead wire is constituted, for example, by a copper or aluminum conductorand an insulation film covering an outer periphery of the conductor.

Generally, a stator winding is formed by a plurality of phases of statorwinding portions, such as star-connected or delta-connected first tothird phases (U-, V- and W-phases) of stator winding portions. Thestator winding portions include a plurality of winding portionsconnected in series or in parallel. Each of the winding portions has awinding part wound around a tooth and a pair of extensions (a firstextension and a second extension) extending continuously from both endsof the winding part.

An extension of one of a pair of the winding parts is continuouslyconnected to an extension of the other winding part, and the extensionsform a crossover wire for connecting the two winding parts.

The electrical insulator assembly has an outer wall part extending in acircumferential direction. The outer wall part has a plurality ofnotches in which the crossover wire is guided. For example, thecrossover wire is drawn from the inside to the outside of the outer wallpart via any one of the notches and guided along the outer peripheralsurface of the outer wall part and then drawn back from the outside tothe inside of the outer wall part via another notch.

Such a technique for guiding a crossover wire is disclosed, for example,in Japanese Unexamined Patent Application Publication No. 2020-162316.

The crossover wire may project outward of the outer wall part when drawnback from the outside to the inside of the outer wall part. If thecrossover wire projects outward of the outer wall part, the insulationdistance between the crossover wire and other parts adjacent to theelectrical insulator assembly may be shortened, or the crossover wiremay come into contact with other parts.

In the above-mentioned known motor, a projection is provided on theouter wall part of the electrical insulator assembly in order tosuppress outward projection of the crossover wire.

In this known motor, however, it is necessary to provide the projectionon the outer wall part of the electrical insulator assembly.

SUMMARY

Accordingly, it is one non-limiting aspect of the present disclosure toprovide a technique for suppressing outward projection of extensionsextending from a winding part outward of an outer wall part of anelectrical insulator assembly. This (suppressing outward projection ofthe extensions outward of the outer wall part of the electricalinsulator assembly) also suppresses outward projection of a crossoverwire formed by two extensions of the respective winding parts.

A first aspect of the present disclosure relates to a motor.

The motor of the present disclosure comprises a stator and a rotor thatis rotatable relative to the stator. Known rotors of variousconfigurations can be used as the rotor.

The stator has a stator core, a plurality of electrical insulatorassemblies and a stator winding.

The stator core is formed, for example, of a lamination ofelectromagnetic steel sheets. The stator core has a yoke extendingannularly around an axis of the stator core and a plurality of teethextending radially inward from the yoke.

The electrical insulator assemblies include a first electrical insulatorassembly arranged on a first stator core end surface on a first side ofthe stator core in an axial direction and a second electrical insulatorassembly arranged on a second stator core end surface on a second sideof the stator core in the axial direction. Each of the first electricalinsulator assembly and the second electrical insulator assembly has anouter wall part and a plurality of extending parts. The outer wall partextends in a circumferential direction and is arranged to face the yoke.The extending parts extend radially inward from the outer wall part andeach of the extending parts is arranged to face the tooth.

The stator winding is formed by a plurality of winding phases, Each ofthe winding phases has a plurality of winding portions. Each of thewinding portions has a winding part wound around the tooth of the statorcore and the extending parts of the first electrical insulator assemblyand the second electrical insulator assembly and a pair of extensionscontinuously extending from a first end and a second end of the windingpart, respectively.

The outer wall part has a prescribed radial thickness and has an innerperipheral surface and an outer peripheral surface. The outer wall parthas a plurality of notches extending radially therethrough andconfigured to guide the extensions between the inner peripheral surfaceand the outer peripheral surface.

Further, the outer wall part is notched from the outer peripheralsurface side such that the radial thickness gradually decreases towardthe notch along a circumferential direction of the yoke of the statorcore. The notch may just be formed in the electrical insulator assemblyon which the extensions are guided. In other words, the notches may beprovided only where an extension needs to pass through the outer wallpart.

The motor of this disclosure can suppress, with a simple structure,outward projection of the extensions extending from the winding partoutward of the outer wall part of the electrical insulator assembly.

In another embodiment of the motor of this disclosure, the stator has acover that is removably mounted onto at least one of the firstelectrical insulator assembly and the second electrical insulatorassembly.

The cover has an outer peripheral wall, an inner peripheral wall and abottom wall. The outer peripheral wall extends in the circumferentialdirection and is arranged outside of the outer peripheral surface of theouter wall part. The inner peripheral wall extends in thecircumferential direction and is arranged to face the inner peripheralsurface of the outer peripheral wall in the radial direction. The bottomwall connects the outer peripheral wall and the inner peripheral wall.

The cover is mounted onto the electrical insulator assembly such thatpart of the winding part is covered by the bottom wall on the outside ofthe inner peripheral wall in the radial direction, while another part ofthe winding part is exposed on the inside of the inner peripheral wallin the radial direction.

Axial movement of the extensions extending from the winding part isrestricted by the cover.

In this embodiment, movement of the extensions along the axial directioncan be suppressed.

In another embodiment of the motor of this disclosure, the bottom wallhas a through hole formed therethrough in the axial direction.

In this embodiment, a temperature rise within the cover can besuppressed.

In another embodiment of the motor of this disclosure, an interphaseinsulation member is provided between the winding parts of differentwinding phases adjacent to each other, within a slot defined between theteeth adjacent to each other.

Movement of the interphase insulation member toward the at least oneelectrical insulator assembly in the axial direction is restricted bythe inner peripheral wall of the cover.

In this embodiment, the length of the interphase insulation member onthe at least one electrical insulator assembly side can be increased sothat the insulation distance on the at least one electrical insulatorassembly side can be increased.

In this embodiment, the electrical insulating properties of theinterphase insulation member along the axial direction can be enhanced.

In another embodiment of the motor of this disclosure, the winding partis wound from the outer wall side of one of the first electricalinsulator assembly and second electrical insulator assembly. Thus, oneof the pair of the extensions is a winding start wire that extendscontinuously to the winding part on the outer wall side of the oneelectrical insulator assembly.

At least one of the winding start wires is covered with an insulationtube and is drawn out from the inner peripheral surface side to theouter peripheral surface side of the outer wall part via one of thenotches and then drawn back from the outer peripheral surface side tothe inner peripheral surface side of the outer wall part via another oneof the notches. The drawn-back winding start wire and the insulationtube are arranged to overlap with the winding part in the axialdirection.

In this embodiment, the winding start wire covered with the insulationtube can be passed to the outside of the outer wall part so that theinsulation distance from the winding start wire can be ensured when thewinding part is wound.

In this embodiment, the insulation strength can be enhanced.

In another embodiment of the motor of this disclosure, the statorwinding is formed by a first winding phase to a third winding phasewhich are star-connected.

A neutral point of the first winding phase to the third winding phase iscovered with an insulation member. The insulation member covering theneutral point is mounted to the insulation tube covering the windingstart wire.

In this embodiment, damage to other parts due to movement of the neutralpoint can be prevented.

In another embodiment of the motor of this disclosure, the statorwinding is formed by a first winding phase to a third winding phasewhich are star-connected.

A neutral point of the first winding phase to the third winding phase iscovered with an insulation member. The insulation member covering theneutral point is arranged between the winding portions adjacent to eachother.

Where an interphase insulation member is arranged between the windingparts of different phases that are respectively wound around the twoadjacent teeth, the insulation member covering the neutral point may bearranged in the interphase insulation member.

In this embodiment, damage to other parts due to movement of the neutralpoint can be prevented.

A second aspect of the present disclosure relates to a compressor.

The compressor of this disclosure has a compression mechanism forcompressing refrigerant and a motor for driving the compressionmechanism. Any one of the motors described above in the first aspect isused as the motor.

Known compression mechanisms of various configurations can be used asthe compression mechanism for compressing refrigerant.

The compressor of this disclosure has the same effect as any one of theabove-described motors of the first aspect.

By using the motor and the compressor of the present disclosure, outwardprojection of the crossover wire outward of the outer wall part of theelectrical insulator assembly is suppressed with a simple structure.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a stator for a motor according to afirst embodiment of the present disclosure.

FIG. 2 is a perspective view of the stator shown in FIG. 1 with a coverremoved.

FIG. 3 is a perspective view of a first electrical insulator assembly ofthe stator used in the motor according to the first embodiment.

FIG. 4 is a perspective view of a second electrical insulator assemblyof the stator used in the motor according to the first embodiment.

FIG. 5 schematically illustrates a relationship of a stator core, slotinsulation members, interface insulation members and the electricalinsulator assemblies in the stator used in the motor according to thefirst embodiment.

FIGS. 6A and 6B are perspective views of significant parts of the firstelectrical insulator assembly of the stator used in the motor accordingto the first embodiment.

FIGS. 7A and 7B are sectional views of the first electrical insulatorassembly of the stator used in the motor according to the firstembodiment.

FIG. 8A is a perspective view of a winding part.

FIG. 8B is a sectional view taken in the direction of line b-b in FIG.8A.

FIGS. 9A and 9B are sectional views of a part corresponding to a notchin the outer wall part of the second electrical insulator assembly ofthe stator used in the motor according to the first embodiment.

FIG. 10 is a perspective view of a slot insulation member of the statorused in the motor according to the first embodiment.

FIG. 11 is a perspective view of an interphase insulation member of thestator used in the motor according to the first embodiment.

FIG. 12 is a perspective view illustrating how to insert the interphaseinsulation member into a slot.

FIG. 13 is a perspective view illustrating how to insert the interphaseinsulation member into the slot.

FIG. 14 is a perspective view of a cover of the stator used in the motoraccording to the first embodiment.

FIG. 15 is a perspective view of the cover of the stator used in themotor according to the first embodiment, as viewed from the back.

FIG. 16 is a perspective view of a locking piece of the cover of thestator used in the motor according to the first embodiment.

FIG. 17 is a sectional elevational view of a mounting mechanism formounting the cover to the second electrical insulator assembly.

FIG. 18 is a perspective view showing the cover mounted to the secondelectrical insulator assembly.

FIG. 19A is a perspective view of a resin film rolled into a tube.

FIG. 19B is a perspective view of an insulation member for covering aneutral point formed from the resin film of FIG. 19A.

FIG. 20 is a perspective view of an example of an arrangement of theinsulation member that covers the neutral point.

FIG. 21 is a perspective view of another example of an arrangement ofthe insulation member that covers the neutral point.

FIG. 22 is a perspective view of a stator used in a motor according to asecond embodiment of the present disclosure.

FIG. 23 is a perspective view of the stator shown in FIG. 22 , with acover removed.

FIG. 24 is a schematic view showing a compressor according to oneembodiment of the present disclosure.

DETAILED DESCRIPTION OF THE EMBODIMENTS

A representative embodiment according to the present disclosure is nowdescribed with reference to the drawings.

In this description, the term “axial direction” refers to an extendingdirection (x direction shown in the Figures) of an axis P of a statorcore. The axis P of the stator core corresponds to a rotation centerline of a rotor when the rotor is arranged to be rotatable relative to astator. Further, the side shown by arrow x1 in the Figures (e.g. upperside in FIGS. 1 and 2 ) and the side shown by arrow x2 in the Figures(e.g. lower side in FIGS. 1 and 2 ) are defined as a “first side in theaxial direction” and a “second side in the axial direction”,respectively.

The term “circumferential direction” refers to a circumferentialdirection (z direction shown in the Figures) around the axis P as viewedfrom the first or second side in the axial direction. Further, in thecircumferential direction around the axis P, as viewed from the firstside in the axial direction, the clockwise side (shown by arrow “z1” inthe Figures) and the counterclockwise side (shown by arrow “z2” in theFigures) are defined as a “first side in the circumferential direction”and a “second side in the circumferential direction”, respectively.

The terms “radially” and “radial direction” refer to an extendingdirection (y direction shown in the Figures) of a line passing throughthe axis P as viewed from the first or second side in the axialdirection. Further, in the radial direction, the side of the axis P(shown by arrow “y1” in the Figures) and the other side opposite fromthe axis P (shown by arrow “y2” in the Figures) are defined as the“inside in the radial direction” or a “first side in the radialdirection”, and the “outside in the radial direction” or a “second sidein the radial direction”, respectively.

As for electrical insulator assemblies (first and second electricalinsulator assemblies), slot insulation members, interphase insulationmembers and a cover, the terms “axial direction”, “circumferentialdirection” and “radial direction” respectively refer to the “axialdirection”, “circumferential direction” and “radial direction” in thestate in which each is mounted on the stator core.

The “first side in the axial direction” and the “second side in theaxial direction”, or the “first side in the circumferential direction”and the “second side in the circumferential direction” may be used inreverse.

Although an aspect of the present disclosure is to suppress outwardprojection of extensions extending from both ends of a winding part,outward of an outer wall part of an electrical insulator assembly, foreasier understanding, a method of processing extensions and a method ofprocessing crossover wires formed by the extensions are described in thefollowing description.

A stator 10 that forms a motor according a first embodiment of thepresent disclosure is now described with reference to FIGS. 1 and 2 .

The stator 10 includes a stator core 100, a first electrical insulatorassembly 200, a second electrical insulator assembly 300, slotinsulation members 120, stator windings (coils) 130, interphaseinsulation members 170 and a cover 400.

The stator core 100 is formed of a stack of a plurality ofelectromagnetic steel sheets (laminations).

The stator core 100 has a tubular shape and has a stator core endsurface (first stator core end surface) 100A and a stator core endsurface (second stator core end surface) 100B respectively on the firstside and the second side in the axial direction.

As shown in FIG. 5 , the stator core 100 includes a yoke 111, aplurality of teeth 112 and a plurality of slots 115.

The yoke 111 extends in the circumferential direction. In thisembodiment, the yoke 111 is annular.

The teeth 112 are spaced apart from each other in the circumferentialdirection and extend radially inward from the yoke 111. Each of theteeth 112 has a tooth base part 113 that extends radially inward fromthe yoke 111 and a tooth tip part 114 that is formed on a radially innerend of the tooth base part 113 and that extends in the circumferentialdirection.

The tooth base part 113 has a first tooth base part side surface 113 aon the first side in the circumferential direction and a second toothbase part side surface 113 b on the second side in the circumferentialdirection.

The tooth tip part 114 has a tooth tip part inner peripheral surface 114a on the radially inner side, a first tooth tip part outer peripheralsurface 114 b on the radially outer side on the first side in thecircumferential direction, and a second tooth tip part outer peripheralsurface 114 c on the radially outer side on the second side in thecircumferential direction.

The tooth tip part 114 has a first tooth projection 114A and a secondtooth projection 114B that respectively protrude to the first side andthe second side in the circumferential direction from the tooth basepart 113. The first tooth projection 114A is defined by the tooth tippart inner peripheral surface 114 a and the first tooth tip part outerperipheral surface 114 b, and the second tooth projection 114B isdefined by the tooth tip part inner peripheral surface 114 a and thesecond tooth tip part outer peripheral surface 114 c.

In this embodiment, the first tooth projection 114A and the second toothprojection 114B correspond to a non-limiting embodiment of a “pair oftooth projections” according to this disclosure.

The tooth tip part inner peripheral surfaces 114 a define a stator coreinner space 100 a.

A rotor (not shown in FIGS. 1 and 2 ) is rotatably arranged within thestator core inner space 100 a. Known rotors of various configurationscan be used as the rotor.

The stator 10 and the rotor arranged within the stator core inner space100 a form the motor according to the first embodiment of the presentdisclosure.

The motor of the first embodiment can be used, for example, as a motorfor driving a compression mechanism for compressing refrigerant. Knowncompression mechanisms of various configurations can be used as thecompression mechanism for compressing refrigerant.

A compressor that has a compression mechanism and the motor of the firstembodiment corresponds to a compressor according to one embodiment ofthis disclosure. The compressor of this embodiment according to thisdisclosure is described later with reference to FIG. 24 .

Each pair of the teeth 112 adjacent to each other in the circumferentialdirection and the yoke 111 define a slot 115. More specifically, theslot 115 is defined by a yoke inner peripheral surface 111 a of the yoke111, the second tooth base part side surface 113 b and the second toothtip part outer peripheral surface 114 c of the tooth 112 arranged on thefirst side in the circumferential direction, and the first tooth basepart side surface 113 a and the first tooth tip part outer peripheralsurface 114 b of the tooth 112 arranged on the second side in thecircumferential direction. A slot opening 115 a is formed between thetooth tip parts 114 of the adjacent teeth 112.

A slot insulation member is inserted in the slot 115.

In this embodiment, the slot insulation member 120 shown in FIG. 10 isused.

The slot insulation member 120 is formed by folding a rectangularsheet-like resin film formed of resin (polymer) having electricalinsulating properties. Resin films made of various kinds of known resincan be used.

Specifically, the slot insulation member 120 is formed by folding therectangular insulation film, which has edges 120 a and 120 b extendingin the axial direction and edges 120 c and 120 d extending in adirection that intersects (crosses) the axial direction, along foldinglines 120A to 120D extending in parallel (or substantially in parallel)to the edges 120 a and 120 b. The slot insulation member 120 is dividedinto a first end part 121, a first intermediate part 122, a central part123, a second intermediate part 124 and a second end part 125 by thefolding lines 120A to 120D.

The first intermediate part 122, the central part 123 and the secondintermediate part 124 are folded into a generally U-shape, and togetherform a body of the slot insulation member. Further, the first end part121 and the second end part 125 are folded toward the inside of theU-shape such that the edges 120 a and 120 b come close to each other.

As shown in FIG. 5 , the body of the slot insulation member 120 isarranged over the yoke inner peripheral surface 111 a and the secondtooth base part side surface 113 b of the tooth 112 arranged on thefirst side in the circumferential direction and the first tooth basepart side surface 113 a of the tooth 112 arranged on the second side inthe circumferential direction. Further, the first end part 121 isarranged to face the second tooth tip part outer peripheral surface 114c of the tooth 112 arranged on the first side in the circumferentialdirection, and the second end part 125 is arranged to face the firsttooth tip part outer peripheral surface 114 b of the tooth 112 arrangedon the second side in the circumferential direction.

The slot insulation member 120 is folded such that when the slotinsulation member 120 is inserted into the slot 115, a distance betweenthe first end part 121 and the second tooth tip part outer peripheralsurface 114 c of the tooth 112 arranged on the first side in thecircumferential direction gradually increases toward the second side inthe circumferential direction. Similarly, the slot insulation member 120is folded such that a distance between the second end part 125 and thefirst tooth tip part outer peripheral surface 114 b of the tooth 112arranged on the second side in the circumferential direction graduallyincreases toward the first side in the circumferential direction.

The slot insulation member 120 corresponds to a non-limiting embodimentof a “first insulation member” according to this disclosure. The firstintermediate part 122, the central part 123 and the second intermediatepart 124 together form a “body of the first insulation member” accordingto this disclosure. The first end part 121 and the second end part 125correspond to a non-limiting embodiment of a “pair of first end parts ofthe first insulation member” according to this disclosure.

In FIG. 5 , the slot insulation member 120 is inserted into the slot 115such that the first end part 121 is arranged on the first side in thecircumferential direction and the second end part 125 is arranged on thesecond side in the circumferential direction. The slot insulation member120 can also be inserted into the slot 115 such that the first end part121 is arranged on the second side in the circumferential direction andthe second end part 125 is arranged on the first side in thecircumferential direction.

In this case, the end part 121 and the intermediate part 122 correspondto the second end part and the second intermediate part, respectively,and the end part 125 and the intermediate part 124 correspond to thefirst end part and the first intermediate part, respectively.

As shown in FIG. 2 , the first electrical insulator assembly 200 and thesecond electrical insulator assembly 300 are arranged on stator core endsurfaces on both sides of the stator core 100 in the axial direction,respectively. In the first embodiment, the first electrical insulatorassembly 200 is arranged on the stator core end surface (first statorcore end surface) 100A on the first side of the stator core 100 in theaxial direction such that an electrical insulator assembly end surface250A of the first electrical insulator assembly 200 faces the statorcore end surface 100A. Further, the second electrical insulator assembly300 is arranged on the stator core end surface (second stator core endsurface) 100B on the second side of the stator core 100 in the axialdirection such that an electrical insulator assembly end surface 350A ofthe second electrical insulator assembly 300 faces the stator core endsurface 100B.

The first and second electrical insulator assemblies 200, 300 are formedof resin having electrical insulating properties.

The electrical insulator assemblies may also be referred to as“insulating bobbins”, “resin bobbins” or “coil bobbins”.

As shown in FIG. 3 , the first electrical insulator assembly 200 has anouter wall part 210, a plurality of inner wall parts 220 and a pluralityof connection parts 250.

The outer wall part 210 extends in the circumferential direction and theaxial direction. The outer wall part 210 is arranged to face the yoke111 of the stator core 100.

The inner wall parts 220 are arranged radially inside the outer wallpart 210 and extend in the circumferential direction and the axialdirection.

The connection parts 250 extend in the circumferential direction and theradial direction and connect the outer wall part 210 and the inner wallparts 220. The outer wall part 210 is arranged to face the teeth 112(specifically, the tooth base part 113) of the stator core 100.

As shown in FIGS. 5, 6A and 6B, each of the inner wall parts 220 has afirst flange 230 and a second flange 240 that respectively protrude tothe first side and the second side in the circumferential direction.FIG. 6B is a perspective view of the inner wall part 220 as viewed froma direction of arrow b in FIG. 6A.

As shown in FIG. 5 , the first flange 230 protrudes to face the slot 115on the first side of the connection part 250 in the circumferentialdirection, and the second flange 240 protrudes to face the slot 115 onthe second side of the connection part 250 in the circumferentialdirection.

The first flange 230 has a first movement restriction surface 231 thatfaces the slot 115 on the first side of the connection part 250 in thecircumferential direction and an outer peripheral surface 232 on thefirst side in the circumferential direction.

The first flange 230 further has a first inner wall projection 233 thatprotrudes to the second side in the axial direction (to the side of thestator core end surface 100A). The first inner wall projection 233 hasan end surface 233 a on the radially inner side and a side surface 233 bon the second side in the circumferential direction.

The first movement restriction surface 231, the end surface 233 a of thefirst inner wall projection 233 and a first side surface 252 of theconnection part 250 define a recess 230 a that is open to the first sidein the circumferential direction and the second side in the axialdirection. The first side surface 252 of the connection part 250 and theside surface 233 b of the first inner wall projection 233 define arecess 230 b that is open to the second side in the axial direction andradially outwardly and inwardly.

The second flange 240 has a second movement restriction surface 241 thatfaces the slot 115 on the second side of the connection part 250 in thecircumferential direction, and an outer peripheral surface 242 on thesecond side in the circumferential direction.

The second flange 240 further has a second inner wall projection 243that protrudes to the second side in the axial direction (to the side ofthe stator core end surface 100A). The second inner wall projection 243has an end surface 243 a on the radially inner side, and a side surface243 b on the first side in the circumferential direction.

The second movement restriction surface 241, the end surface 243 a ofthe second inner wall projection 243 and a second side surface 253 ofthe connection part 250 define a recess 240 a that is open to the secondside in the circumferential direction and the second side in the axialdirection. The second side surface 253 of the connection part 250 andthe side surface 243 b of the second inner wall projection 243 define arecess 240 b that is open to the second side in the axial direction andradially outwardly and inwardly.

The end surfaces 233 a, 243 a extend in the axial direction and thecircumferential direction.

In this embodiment, the first flange 230 corresponds to a non-limitingembodiment of a “first movement restriction part” according to thisdisclosure. The first movement restriction surface 231 and the endsurface 233 a correspond to non-limiting embodiments of a “first axialmovement restriction surface” and a “first radial movement restrictionsurface” according to this disclosure, respectively.

Further, the second flange 240 corresponds to a non-limiting embodimentof a “second movement restriction part” according to this disclosure.The second movement restriction surface 241 and the end surface 243 acorrespond to non-limiting embodiments of a “second axial movementrestriction surface” and a “second radial movement restriction surface”according to this disclosure, respectively.

Further, as shown in FIG. 4 , like the first electrical insulatorassembly 200, the second electrical insulator assembly 300 has an outerwall part 310, a plurality of inner wall parts 320 and a plurality ofconnection parts 350.

In this embodiment, the connection parts 250 of the first electricalinsulator assembly 200 and the connection parts 350 of the secondelectrical insulator assembly 300 correspond to non-limiting embodimentsof “extending parts extending radially inward from the outer wall part”according to this disclosure.

The inner wall parts 320 of the second electrical insulator assembly 300are configured similarly to the inner wall parts 220 of the firstelectrical insulator assembly 200, and therefore described withreference to FIGS. 6A and 6B. In FIGS. 6A and 6B, reference numerals forelements of the second electrical insulator assembly 300 are shown inparenthesis. In the second electrical insulator assembly 300, which isarranged such that the end surface 350A of the connection part 350 facesthe stator core end surface 100B, the “first side in the axial direction(x1)” and the “second side in the axial direction (x2)”, and the “firstside in the circumferential direction (z1)” and the “second side in thecircumferential direction (z2)” are the opposite of those of the firstelectrical insulator assembly 200.

Each of the inner wall parts 320 has a third flange 330 and a fourthflange 340 that respectively protrude to the first side and the secondside in the circumferential direction. The third flange 330 protrudes toface the slot 115 on the first side of the connection part 350 in thecircumferential direction. The fourth flange 340 protrudes to face theslot 115 on the second side of the connection part 350 in thecircumferential direction.

The third flange 330 has a third movement restriction surface 331 thatfaces the slot 115 and an outer peripheral surface 332 on the first sidein the circumferential direction. The fourth flange 340 has a fourthmovement restriction surface 341 that faces the slot 115 and an outerperipheral surface 342 on the second side in the circumferentialdirection.

The third and fourth movement restriction surfaces 331, 341 extend inthe circumferential direction and the radial direction.

The third flange 330 further has a third inner wall projection 333 thatprotrudes to the first side in the axial direction (to the side of thestator core end surface 100B). The third inner wall projection 333 hasan end surface 333 a on the radially inner side and a side surface 333 bon the second side in the circumferential direction.

The third movement restriction surface 331, the end surface 333 a of thethird inner wall projection 333 and a first side surface 352 of theconnection part 350 of the second electrical insulator assembly 300define a recess 330 a that is open to the first side in thecircumferential direction and the first side in the axial direction. Thefirst side surface 352 of the connection part 350 of the secondelectrical insulator assembly 300 and the side surface 333 b of thethird inner wall projection 333 define a recess 330 b that is open tothe first side in the axial direction and radially outwardly andinwardly.

The fourth flange 340 further has a fourth inner wall projection 343that protrudes to the first side in the axial direction (to the side ofthe stator core end surface 100B). The fourth inner wall projection 343has an end surface 343 a on the radially inner side and a side surface343 b on the first side in the circumferential direction.

The fourth movement restriction surface 341, the end surface 343 a ofthe fourth inner wall projection 343 and a second side surface 353 ofthe connection part 350 of the second electrical insulator assembly 300define a recess 340 a that is open to the second side in thecircumferential direction and the first side in the axial direction. Thesecond side surface 353 of the connection part 350 of the secondelectrical insulator assembly 300 and the side surface 343 b of thefourth inner wall projection 343 define a recess 340 b that is open tothe first side in the axial direction and radially outwardly andinwardly.

In this embodiment, the third flange 330 corresponds to a non-limitingembodiment of a “third movement restriction part” according to thisdisclosure. The third movement restriction surface 331 and the endsurface 333 a correspond to non-limiting embodiments of a “third axialmovement restriction surface” and a “third radial movement restrictionsurface” according to this disclosure, respectively.

Further, the fourth flange 340 corresponds to a non-limiting embodimentof a “fourth movement restriction part” according to this disclosure.The fourth movement restriction surface 341 and the end surface 343 acorrespond to non-limiting embodiments of a “fourth axial movementrestriction surface” and a “fourth radial movement restriction surface”according to this disclosure, respectively.

In the following description, the “electrical insulator assembly” issimply referred to as an “assembly”. Further, the “first electricalinsulator assembly 200” and the “second electrical insulator assembly300” are simply referred to as a “first assembly 200” and a “secondassembly 300”, respectively.

The stator winding 130 is formed by winding a lead wire 132 around theteeth 112 of the stator core 100 and the corresponding connection parts250, 350 of the first and second assemblies 200, 300 (see FIGS. 8A and8B) after the slot insulation members 120 are inserted into the slots115 of the stator core 100 and the first and second assemblies 200, 300are arranged on the opposite sides of the stator core 100 in the axialdirection. Various known methods can be used to wind the lead wire 132.For example, the lead wire 132 can be wound by turning a needle forsupplying the lead wire 132 around the teeth 112 and the connectionparts 250, 350.

The lead wire 132 is constituted, for example, of a copper or aluminumconductor and an insulation film covering an outer periphery of theconductor.

The amount (the number of turns) of the lead wire 132 to be wound andstored in the slot 115 is reduced and thus the space factor is reducedif the lead wires 132 of a plurality of turns cross each other whenwound around each of the teeth 112.

The wound state of the lead wire 132 in a first row around the tooth 112significantly affects whether such crossing of the lead wire 132 occurs.For example, if the lead wire 132 is not wound in alignment in the firstrow, the lead wire 132 is likely to cross the lead wire 132 wound in thesecond row.

In this embodiment, the connection parts 250 of the first assembly 200and the connection parts 350 of the second assembly 300 are configuredto prevent crossing of the lead wire 132.

The connection parts 250, 350 of the first and second assemblies 200,300 have the same shape. Therefore, the shape of the connection part 250of the first assembly 200 is now described with reference to FIGS. 7Aand 7B. FIG. 7A is a sectional view of the first assembly 200 takenalong the radial direction, and FIG. 7B is a sectional view taken alongline b-b in FIG. 7A.

In FIGS. 7A and 7B, reference numerals for elements of the connectionpart 350 of the second assembly 300 are shown in parenthesis.

The connection part 250 has a top surface 251 on the side opposite tothe stator core 100 and has first and second side surfaces 252 and 253respectively formed on the first and second sides in the circumferentialdirection. The top surface 251 extends in the radial direction and thecircumferential direction. The first and second side surfaces 252, 253extend in the axial direction and the radial direction.

A plurality of grooves 254 extending in the circumferential directionare formed in a connection between the top surface 251 and the firstside surface 252. In this embodiment, the grooves 254 are defined by aplurality of projections 254 a extending in parallel (or substantiallyin parallel) in the circumferential direction.

Similarly, a plurality of grooves 255 that are defined by a plurality ofprojections 255 a extending in parallel (or substantially in parallel)in the circumferential direction are formed in a second connectionsurface between the top surface 251 and the second side surface 253.

The lead wire 132 in the first row can be aligned during winding by thegrooves 254 (255) in the connection between the top surface 251 and thefirst side surface 252 (the second side surface 253). This preventscrossing of the lead wire 132 in the second and subsequent rows.

Further, if the projections 254 a (255 a) that define the grooves 254(255) each have a sharp protruding end, the insulation film of the leadwire 132 arranged in the grooves 254 (255) may be damaged. It istherefore preferable that each of the projections 254 a (255 a) does nothave a sharp protruding end. The description that “the projection doesnot have a sharp protruding end” means that “the projection does nothave a protruding end sharpened at an acute angle”. The projection nothaving a sharp protruding end corresponds, for example, to a projectionhaving a protruding end surface of a curved shape including acircular-arc shape (round shape), or a flat shape.

Further, a stepped surface 256 is formed between the top surface 251 ofthe connection part 250 and an inner peripheral surface 211 of the outerwall part 210 and protrudes to the side opposite to the stator core 100.

Similarly, a stepped surface 257 is formed between the top surface 251of the connection part 250 and an outer peripheral surface 222 of theinner wall part 220 and protrudes to the side opposite to the statorcore 100.

The lead wire 132 of the first row can be aligned during winding by thestepped surface 256 between the top surface 251 of the connection part250 and the inner peripheral surface 211 of the outer wall part 210, orby the stepped surface 257 between the top surface 251 of the connectionpart 250 and the outer peripheral surface 222 of the inner wall part220.

The height of the stepped surface 256 and the distance between the innerperipheral surface 211 of the outer wall part 210 and the steppedsurface 256, and the height of the stepped surface 257 and the distancebetween the outer peripheral surface 222 of the inner wall part 220 andthe stepped surface 257 are appropriately set such that the lead wire132 can be wound in alignment.

Further, any one of the grooves 254, the grooves 255, the steppedsurface 256 and the stepped surface 257, or any combinationappropriately selected therefrom may be provided.

The end surface 250A of the connection part 250 on the stator core 100side is used as an end surface of the first assembly 200.

The connection part 350 of the second assembly 300 is formed similarlyto the connection part 250 of the first assembly 200.

Specifically, in the connection part 350, a plurality of grooves 354(355) that are defined by a plurality of projections 354 a (355 a) areformed in a connection between a top surface 351 and a first sidesurface 352 (a second side surface 353). Further, a stepped surface 356(357) is formed between the top surface 351 of the connection part 350and an inner peripheral surface 311 of the outer wall part 310 (an outerperipheral surface 322 of the inner wall part 320).

Further, in this embodiment, as shown in FIGS. 7A and 7B, parts of outerand inner peripheral surfaces of the first assembly 200 on the statorcore 100 side are respectively formed as inclined surfaces.

Specifically, a part 212 m of an outer peripheral surface 212 of theouter wall part 210 on the stator core end surface 100A side is formedas an inclined surface that is inclined radially inward such that thedistance between the outer peripheral surface 212 and the stator coreend surface 100A gradually decreases toward the stator core end surface100A. In other words, the inclined surface 212 m is inclined radiallyinward toward the stator core end surface 100A.

Further, a part 221 m of an inner peripheral surface 221 of the innerwall part 220 on the stator core end surface 100A side is formed as aninclined surface that is inclined radially outward such that thedistance between the inner peripheral surface 221 and the stator coreend surface 100A gradually decreases toward the stator core end surface100A. In other words, the inclined surface 221 m is inclined radiallyoutward toward the stator core end surface 100A.

In this embodiment, like in the first assembly 200, parts of outer andinner peripheral surfaces of the second assembly 300 on the stator core100 side are respectively formed as inclined surfaces. Specifically, apart of an outer peripheral surface 312 of the outer wall part 310 onthe stator core end surface 100B side is formed as an inclined surface312 m that is inclined radially inward toward the stator core endsurface 100B. Further, a part of an inner peripheral surface 321 of theinner wall part 320 on the stator core end surface 100B side is formedas an inclined surface 321 m that is inclined radially outward towardthe stator core end surface 100B.

The inclined surface may be a linearly extending surface (taperedsurface) or a surface extending in a curved shape or a stepped shape.

In this embodiment, a lead wire (crossover wire) is not guided on theoutside of the outer wall part 210 of the first assembly 200. In thiscase, the insulation distance (creepage distance) between the lead wirewithin a recess 200 a of the first assembly 200 and the stator core endsurface 100A can be increased by the presence of the inclined surface212 m formed in the outer peripheral surface 212 of the outer wall part210 or the inclined surface 221 m formed in the inner peripheral surface221 of the inner wall part 220.

Further, in this embodiment, a lead wire (crossover wire) is wired onthe outside of the outer wall part 310 of the second assembly 300. Inthis case, the insulation distance (creepage distance) between the leadwire (crossover wire) wired on the outside of the outer wall part 310 ofthe second assembly 300 and the stator core end surface 100B can beincreased by the presence of the inclined surface 312 m formed in theouter peripheral surface 312 of the outer wall part 310. Further, theinsulation distance (creepage distance) between the lead wire within arecess 300 a of the second assembly 300 and the stator core end surface100B can be increased by the presence of the inclined surface 321 mformed in the inner peripheral surface 321 of the inner wall part 320.

The electrical insulating properties of the assemblies can be enhancedby forming the inclined surfaces in parts of the outer and innerperipheral surfaces (the outer peripheral surfaces of the outer wallparts and the inner peripheral surfaces of the inner wall parts) of theassemblies on the stator core side without increasing the height of theassemblies.

The inclined surfaces (the inclined surface of the outer wall part andthe inclined surface of the inner wall part) may be formed on only oneof the first and second assemblies 200, 300. Further, the inclinedsurface may be formed on only one of the outer peripheral surface of theouter wall part and the inner peripheral surface of the inner wall part.

The stator winding 130 is formed by a plurality of phases of statorwinding portions. In this embodiment, it is formed by first to thirdphases (U-, V- and W-phases) of stator winding portions. The statorwinding portion of each phase has a plurality of winding portionsconnected in series or in parallel.

As shown in FIGS. 8A and 8B, each of the winding portions has a windingpart 131 wound around the tooth 112 (more specifically, the tooth 112and the connection parts 250, 350) and a pair of extensions 132 a, 132 bextending continuously from the both ends of the winding part 131. Theextension 132 a is a winding start wire and the extension 132 b is awinding end wire.

The winding part 131 is formed by the lead wire 132 wound around thecorresponding tooth 113 in rows (the first row to the n-th row) from theinner side to the outer side. When current is flowing through the statorwinding 130, a potential difference between the lead wire 132 wound inthe innermost first row and the lead wire 132 wound in the n-th row onthe outer side is large. Therefore, if the lead wire 132 of the firstrow comes into contact with the lead wire 132 of the n-th row, poorinsulation may be caused. The lead wire 132 of the first row extendscontinuously to the winding start wire 132 a. In this case, it isnecessary to prevent contact between the winding start wire 132 a andthe lead wire 132 wound on the outer side.

A method of processing the winding start wire 132 a is now describedwith reference to FIGS. 8A and 8B.

FIG. 8A is an enlarged view of an essential part of the first assembly200. FIG. 8B is a sectional view taken along line b-b in FIG. 8A. InFIG. 8A, only the lead wire 132 of the first row is shown, but actually,as shown in FIG. 8B, the lead wire 132 is wound in a plurality of rows.

In this embodiment, the lead wire 132 is wound around the tooth 112 byinserting a needle for supplying the lead wire 132 into the slot 115from the slot opening 115 a. In this embodiment, winding of the leadwire 132 by the needle is started from a radially outer position (on theouter wall part 210 side) and finished at a radially outer position (onthe outer wall part 210 side). Specifically, the winding start wire 132a and the winding end wire 132 b are arranged on the outer wall part 210side on the first side surface 252 or the second side surface 253 of theconnection part 250.

Therefore, in this embodiment, the outer wall part 210 of the firstassembly 200 has a plurality of grooves 213 formed in positionscorresponding to connections (in the vicinity of connections) with thefirst side surface 252 or the second side surface 253 of the connectionpart 250. The grooves 213 are open to the side opposite to the statorcore 100 in the axial direction and open to the inner peripheral surface211 and the outer peripheral surface 212 of the outer wall part 210.Each of the grooves 213 is defined by a side wall 213 a on the firstside in the circumferential direction, a side wall 213 b on the secondside in the circumferential direction and a bottom wall 213 c.

The winding start wire 132 a is drawn out from the inside of the outerwall part 210 (i.e. passes to the outside of the outer wall part 210)via the groove 213.

The groove 213 is formed to prevent the winding start wire 132 a from atleast coming into contact with or closer than a predetermined distanceto the lead wire 132 of the outermost n-th row. For example, the depthof the groove 213 is set such that a distance H (see FIG. 8B) betweenthe lead wire 132 of the n-th row and the winding start wire 132 a doesnot become a set value or less.

In this embodiment, the winding start wire 132 a (the lead wire 132 ofthe first row) is prevented from coming into contact with or intoproximity to the lead wire 132 of the n-th row by passing the windingstart wire 132 a, which is continuous to the winding part 131 woundaround the tooth 112, to the outside of the outer wall part 210.

At least one of the two end parts of the stator winding portions of thefirst to third phases is connected to a power supply. For example, whenstar-connected, one end part is connected to a power supply and theother end part is connected to a neutral point. When delta-connected,both end parts are connected to a power supply. The end part to beconnected to a power supply is formed by the winding start wire 132 a orthe winding end wire 132 b, which is continuous to the winding part 131that forms the stator winding portion, and referred to as a power supplyside lead wire.

The power supply side lead wire is connected to a power supply and thusneeds to have higher insulation strength. Particularly if formed by thewinding start wire 132 a, the power supply side lead wire needs to beprevented from coming into contact with the lead wire 132 wound on theouter side as described above.

Processing of the winding start wire 132 a in the case where the powersupply side lead wire is formed by the winding start wire 132 a is nowdescribed with reference to FIG. 3 .

The winding start wire 132 a forming the power supply side lead wire iscovered with an insulation tube. The insulation tube is formed, forexample, of resin (polymer) having electrical insulating properties.

The winding start wire 132 a covered with the insulation tube is drawnout from the inner peripheral surface 211 side to the outer peripheralsurface 212 side of the outer wall part 210 via one of the grooves 213formed in the outer wall part 210 of the first assembly 200. Then thewinding start wire 132 a is drawn back from the outer peripheral surface212 side to the inner peripheral surface 211 side of the outer wall part210 via another groove 213. In FIG. 3 , the winding start wire 132 a iswound around a projection formed between the two grooves 213.

The winding start side end part covered with the insulation tube is thenrouted along the first side of the winding part 131 wound around thetooth 112 in the axial direction. Specifically, the winding start sideend part covered with the insulation tube is arranged to overlap withthe winding part 131 when viewed from the first side in the axialdirection.

Where the power supply side lead wire is formed by the winding end wire132 b, the winding end wire 132 b covered with the insulation tube isrouted along the first side in the axial direction of the winding part131.

FIG. 20 shows the power supply side lead wire covered with theinsulation tube routed along the first side in the axial direction ofthe winding part 131.

When continuously forming the winding parts 131, the lead wire 132 isrouted such that one of a pair of the extensions (the winding start wire132 a, the winding end wire 132 b) continuous to one winding part 131 iscontinuously connected to one of a pair of the extensions continuous toanother winding part 131. Thus, a crossover wire for connecting twowinding parts is provided.

In this embodiment, the crossover wire is wired on the second assembly300 side.

As shown in FIG. 4 , a plurality of notches 316 are formed in the outerwall part 310 of the second assembly 300 such that the crossover wire isdrawn out from the inside to the outside of the outer wall part 310 ordrawn back from the outside to the inside of the outer wall part 310through the notches 316. Each of the notches 316 is open to the sideopposite to the stator core 100 and to the outer and inner peripheralsurfaces 312 and 311 of the outer wall part 310. The notch 316 isdefined by a first side wall 316 a on the first side in thecircumferential direction, a second side wall 316 b on the second sidein the circumferential direction and a bottom wall 316 c on the statorcore 100 side.

In this embodiment, three types of notches 316A, 316B, 316C are formedin the outer wall part 310 such that the crossover wires that form thestator winding portions of the first to third phases are drawn out fromthe inside to the outside of the outer wall part 310 or drawn back fromthe outside to the inside of the outer wall part 310 therethrough whilebeing prevented from coming into contact with each other.

Further, guide grooves 315A, 315B, 315C are formed in the outerperipheral surface 312 of the outer wall part 310 to guide the crossoverwires drawn out to the outside of the outer wall part 310, along theouter peripheral surface 312. The guide grooves 315A, 315B, 315C havedifferent axial depths and are spaced apart from each other in thecircumferential direction so as to prevent contact between the crossoverwires respectively inserted into the guide grooves 315A, 315B, 315C.

Each of the crossover wires is drawn out from the inside to the outsideof the outer wall part 310 via one of the notches 316A, 316B, 316C. Thenthe crossover wire is guided via one of the guide grooves 315A, 315B,315C of the outer peripheral surface 312 of the outer wall part 310 tobe guided along the outer peripheral surface 312. Thereafter, thecrossover wire is drawn back from the outside to the inside of the outerwall part 310 via one of the notches 316A, 316B, 316C.

The strength of the outer wall part 310 may be reduced if the notches316A, 316B, 316C have the same depth. Therefore, in this embodiment, thenotches 316A, 316B, 316C are formed to have different depths. Thissuppresses reduction of the strength of the outer wall part 310 due toprovision of the notches 316A, 316B, 316C. Specifically, the tension ofthe crossover wire inserted into the notches 316A, 316B, 316C can be sethigh, so that movement (displacement) of the crossover wire can beprevented.

Conventionally, as shown by broken line in FIGS. 9A and 9B, the outerand inner peripheral surfaces 312 and 311 of the outer wall part 310extend arcuately in parallel with a uniform distance therebetween. Inthis state, the crossover wire is drawn back from the outside to theinside of the outer wall part 310 via the notch 316. In this case, asshown by a thin solid arrow A, the crossover wire may make a large turnin such a manner as to project outward of the outer wall part 310 whenpassed through the notch 316. If projecting outward, the crossover wiremay come into proximity to or into contact with other parts and causeinsulation failure.

In this embodiment, at least the shape of a part of the outer peripheralsurface 312 of the outer wall part 310 where the crossover wire is drawnback from the outside to the inside of the outer wall part 310 ismodified as shown by solid line in FIGS. 9A and 9B. Specifically, theouter peripheral surface 312 of the outer wall part 310 is notched suchthat a distance (radial thickness) L between the outer peripheralsurface 312 and the inner peripheral surface 311 gradually decreasestoward the notch 316 along the circumferential direction. Morespecifically, the inner peripheral surface 311 of the outer wall part310 extends arcuately as conventional. The outer peripheral surface 312also extends arcuately as conventional up to the vicinity of the notch316. The outer wall part 310 is then notched from the outer peripheralsurface 312 side such that the distance L between the outer peripheralsurface 312 and the inner peripheral surface 311 gradually decreasestoward the notch 316 from the front vicinity of the notch 316 along thecircumferential direction (L2<L1). In this embodiment, the outer wallpart 310 is notched such that a linearly extending inclined surface 312a is formed on the outer peripheral surface 312 side.

The shape of the inclined surface 312 a is not limited to this. Forexample, in an example shown in FIG. 9B, the inclined surface 312 a hasa circular arc shape curved radially outward.

Where the crossover wire is drawn through the notch 316 in a clockwisedirection, the outer peripheral surface 312 of the outer wall part 310is notched to form an inclined surface 312 b.

This configuration of the outer peripheral surface 312 of the outer wallpart 310, which is notched such that the distance (radial thickness)between the outer peripheral surface 312 and the inner peripheralsurface 311 gradually decreases toward the notch 316 in the vicinity ofthe notch 316, suppresses outward projection of the crossover wireoutward of the outer wall part 310 as shown by bold arrow B in FIGS. 9Aand 9B.

The outer wall part 210, the inner wall parts 220 and the connectionparts 250 of the first assembly 200 respectively have the samestructures as the outer wall part 310, the inner wall parts 320 and theconnection parts 350 of the second assembly 300, except for thestructure (the grooves 213 through which the winding start wire ispassed) for passing the winding start wire continuous to the windingpart to the outside of the outer wall part, and the structure (the guidegrooves 315A, 315B, 315C for guiding the wiring position of thecrossover wires, the notches 316A, 316B, 316C through which thecrossover wires are passed between the inside and the outside of theouter wall part) for wiring the crossover wires between the differentwinding parts via the outer peripheral surface of the outer wall part.The first assembly 200 and the second assembly 300 may have the samestructure.

In this embodiment, on the first assembly 200 side, the power supplyside lead wire of each of the stator winding portions that is connectedto a power supply is routed along the circumferential direction withinthe recess 200 a of the first assembly 200. Where the stator windingportion is star-connected, a neutral point side lead wire of the statorwinding portion that is connected to a neutral point is also routedalong the circumferential direction within the recess 200 a of the firstassembly 200 while being connected in common to the neutral point. Forexample, as shown in FIG. 20 , the power supply side lead wires (160U,160V) and the neutral point side lead wires (130Ub, 130Vb, 130Wb) arelaid in this order on the side opposite to the stator core 100 relativeto the winding part 131 of the stator winding 130. In FIG. 20 , thepower supply side lead wire (160W) is hidden.

The power supply side lead wires and the neutral point side lead wiresare fixed to the first assembly 200, for example, with a binding stringso as to be prevented from being moved (displaced).

In this embodiment, as shown in FIG. 13 , thin parts 215 are formed inthe outer wall part 210 of the first assembly 200.

Further, communication holes 216 are formed adjacent to the thin parts215 and are open to the inner peripheral surface 211 and the outerperipheral surface 212 of the outer wall part 210.

The thin parts 215 are formed radially inward of the outer peripheralsurface 212 of the outer wall part 210. Thus, a working space is createdbetween the thin parts 215 and the outer peripheral surface 212 of theouter wall part 210.

The communication holes 216 are formed adjacent to the thin parts 215 inthe axial direction to extend in the circumferential direction.

With this configuration, where the power supply side lead wires and theneutral point side lead wires are fixed by using a binding string 180passed through the communication hole 216, the binding string 180 isprevented from projecting outward from the outer peripheral surface 212of the outer wall part 210.

The interphase insulation member 170 is now described.

In this embodiment, the interphase insulation member 170 shown in FIG.11 is used.

The interphase insulation member 170 is formed by folding a resin filmhaving electrical insulating properties.

The interphase insulation member 170 is formed by folding a rectangularinsulation film, which has edges 170 a and 170 b extending in the axialdirection and edges 170 c and 170 d extending in a direction crossingthe axial direction, along folding lines 170A, 170B, 170C extending inparallel (or substantially in parallel) to the edges 170 a and 170 b.The interphase insulation member 170 is divided into a first end part171, a first central part 172, a second central part 173 and a secondend part 174 by the folding lines 170A, 170B, 170C.

The first central part 172 and the second central part 173 of the foldedfilm form a V-shape. Further, the first and second end parts 171, 174are folded in directions away from each other.

The interphase insulation member 170 corresponds to a non-limitingembodiment of a “second insulation member” according to this disclosure.The first central part 172 and the second central part 173 form an“interphase insulation part of the second insulation member” of thisdisclosure. The first and second end parts 171, 174 correspond to anon-limiting embodiment of a “pair of second end parts of the secondinsulation member” according to this disclosure.

A method of inserting the interphase insulation member 170 is nowdescribed.

First, with reference to FIGS. 5, 6A and 6B, the insertion of the slotinsulation member 120 into the slot 115 of the stator core 110 and thearrangement of the first and second assemblies 200, 300 on the oppositesides of the stator core 100 in the axial direction are described.

The body of the slot insulation member 120 is arranged over the yokeinner peripheral surface 111 a, the second tooth base part side surface113 b of the tooth 112 arranged on the first side in the circumferentialdirection and the first tooth base part side surface 113 a of the tooth112 arranged on the second side in the circumferential direction.Further, the first end part 121 and the second end part 125 are arrangedto face the second tooth tip part outer peripheral surface 114 c of thetooth 112 arranged on the first side in the circumferential directionand the first tooth tip part outer peripheral surface 114 b of the tooth112 arranged on the second side in the circumferential direction,respectively.

In this state, the first and second assemblies 200 and 300 are arrangedon the opposite sides of the stator core 100 in the axial direction.

At this time, the inner wall part 220 of the first assembly 200 and theinner wall part 320 of the second assembly 300 restrict radially outwardmovement of the slot insulation member 120.

Specifically, the first end part 121 and the first intermediate part 122are arranged within a recess 240 a and a recess 240 b of one of theadjacent inner wall parts 220 that is located on the first side in thecircumferential direction. Thus, the folding line 120A between the firstend part 121 and the first intermediate part 122 is arranged radiallyinside of the inner wall projection 243. Further, the first end part 121and the first intermediate part 122 are arranged within a recess 330 aand a recess 330 b of one of the adjacent inner wall parts 320 that islocated on the first side in the circumferential direction. Thus, thefolding line 120A between the first end part 121 and the firstintermediate part 122 is arranged radially inside of the inner wallprojection 333.

The second end part 125 and the second intermediate part 124 arearranged within the recess 230 a and the recess 230 b of one of theadjacent inner wall parts 220 that is located on the second side in thecircumferential direction. Thus, the folding line 120D between thesecond end part 125 and the second intermediate part 124 is arrangedradially inside of the inner wall projection 233. Further, the secondend part 125 and the second intermediate part 124 are arranged within arecess 340 a and a recess 340 b of one of the adjacent inner wall parts320 that is located on the second side in the circumferential direction.Thus, the folding line 120D between the second end part 125 and thesecond intermediate part 124 is arranged radially inside of the innerwall projection 343.

In this case, the inner wall projection 243 of the inner wall part 220of the first assembly 200 and the inner wall projection 333 of the innerwall part 320 of the second assembly 300 restrict radially outwardmovement of the first end part 121. Further, the inner wall projection233 of the inner wall part 220 of the first assembly 200 and the innerwall projection 343 of the inner wall part 320 of the second assembly300 restrict radially outward movement of the second end part 125.

In this manner, radially outward movement of the first and second endparts 121, 125 (the slot insulation member 120) is restricted while aspace is formed between the first end part 121 of the slot insulationmember 120 and the second tooth tip part outer peripheral surface 114 cof the tooth 112 arranged on the first side in the circumferentialdirection and between the second end part 125 of the slot insulationmember 120 and the first tooth tip part outer peripheral surface 114 bof the tooth 112 arranged on the second side in the circumferentialdirection.

Axial movement of the slot insulation member 120 is restricted by theinner wall part 220 of the first assembly 200 and the inner wall part320 of the second assembly 300.

Specifically, axial movement of the first end part 121 is restricted bythe second movement restriction surface 241 of the inner wall part 220and the fourth movement restriction surface 341 of the inner wall part320 that are arranged on the first side in the circumferentialdirection. Further, axial movement of the second end part 125 isrestricted by the first movement restriction surface 231 of the innerwall part 220 and the third movement restriction surface 331 of theinner wall part 320 that are arranged on the second side in thecircumferential direction.

Insertion of the interphase insulation member 170 into the slot 115 isnow described with reference to FIGS. 5, 12 and 13 .

The first end part 171 of the interphase insulation member 170 isarranged within a region defined by the first end part 121 of the slotinsulation member 120 and the second tooth tip part outer peripheralsurface 114 c of one of the teeth 112 defining the slot 115, which isarranged on the first side in the circumferential direction. Further,the second end part 174 is arranged within a region defined by thesecond end part 125 of the slot insulation member 120 and the firsttooth tip part outer peripheral surface 114 b of one of the teeth 112defining the slot 115, which is arranged on the second side in thecircumferential direction. Further, the interphase insulation part (thefirst central part 172 and the second central part 173) is arrangedbetween the winding parts 131 of different phases that are respectivelywound around the teeth 112 adjacent to each other in the circumferentialdirection.

When inserting the interphase insulation member 170 into the slot 115,the interphase insulation member 170 is folded such that the distancebetween the edges 170 a and 170 b is reduced as shown in FIG. 12 .

In this state, from the edge on the first side in the axial direction(e.g. the edge 170 c), the first and second end parts 171, 174 arerespectively inserted between outer peripheral surfaces of therespectively corresponding inner wall parts 320 of the second assembly300 and tooth tip part outer peripheral surfaces of the respectivelycorresponding teeth 112, and the interphase insulation part is insertedbetween the adjacent winding parts 131 of different phases.

Specifically, the first end part 171 is inserted between the outerperipheral surface 342 of the inner wall part 320 and the second toothtip part outer peripheral surface 114 c of the tooth 112 so as to bearranged radially inside the first end part 121 of the slot insulationmember 120. Further, the second end part 174 is inserted between theouter peripheral surface 332 of the inner wall part 320 and the firsttooth tip part outer peripheral surface 114 b of the tooth 112 so as tobe arranged radially inside the second end part 125 of the slotinsulation member 120.

Further, the interphase insulation part is inserted between the windingparts 131 of different phases wound around the adjacent teeth 112 frombetween the adjacent inner wall parts 320.

The first end part 171 of the interphase insulation member 170 isarranged in a space defined by the tooth tip part outer peripheralsurface 114 c of the tooth 112 and the first end part 121 of the slotinsulation member 120, and the second end part 174 of the interphaseinsulation member 170 is arranged in a space defined by the tooth tippart outer peripheral surface 114 b of the tooth 112 and the second endpart 125 of the slot insulation member 120. This arrangement enhancesthe insulation strength. For example, even if the interphase insulationmember 170 is displaced (moved), a gap is prevented from being formedbetween the interphase insulation member 170 (the first end part 171,the second end part 174) and the slot insulation member 120 (the firstend part 121, the second end part 125). Thus, insulation failure due tomovement of the interphase insulation member 170 is prevented.

The operation of inserting the interphase insulation member 170 into theslot 115 along the axial direction is completed when the first end part171 abuts on the second movement restriction surface 241 of the innerwall part 220 of the first assembly 200 that is arranged on the firstside in the circumferential direction, or when the second end part 174abuts on the first movement restriction surface 231 of the inner wallpart 220 of the first assembly 200 that is arranged on the second sidein the circumferential direction, as shown in FIG. 13 .

Upon completion of insertion into the slot 115, external force forshortening the distance between the edges 170 a and 170 b is released,so that the interphase insulation member 170 returns to its originalshape by elastic force. Specifically, the first end part 171 of theinterphase insulation member 170 is arranged within the recess 240 a ofthe inner wall part 220 arranged on the first side in thecircumferential direction, and the second end part 174 is arrangedwithin the recess 230 a of the inner wall part 220 arranged on thesecond side in the circumferential direction.

Axial movement of the interphase insulation member 170 is restricted bythe inner wall part 220 of the first assembly 200 and the inner wallpart 320 of the second assembly 300. Specifically, axial movement of thefirst end part 171 is restricted by the second movement restrictionsurface 241 of the inner wall part 220 and the fourth movementrestriction surface 341 of the inner wall part 320 that are arranged onthe first side in the circumferential direction. Further, axial movementof the second end part 174 is restricted by the first movementrestriction surface 231 of the inner wall part 220 and the thirdmovement restriction surface 331 of the inner wall part 320 that arearranged on the second side in the circumferential direction.

In FIG. 5 , the interphase insulation member 170 is inserted into theslot 115 such that the first end part 171 is arranged on the first sidein the circumferential direction, while the second end part 174 isarranged on the second side in the circumferential direction. Theinserting method of the interphase insulation member 170 is not limitedto this. For example, the interphase insulation member 170 may beinserted into the slot 115 such that the first end part 171 is arrangedon the second side in the circumferential direction, while the secondend part 174 is arranged on the first side in the circumferentialdirection.

In this case, the end part 171 and the central part 172 correspond tothe second end part and the second central part, respectively, and theend part 174 and the central part 173 correspond to the first end partand the first central part, respectively.

It may be desired to enhance the insulation strength along the axialdirection by increasing the axial length of the interphase insulationmember 170. For example, it may be desired to use an interphaseinsulation member 170 that is longer than the distance between the firstand second assemblies 200, 300 arranged on the opposite sides of thestator core 100 in the axial direction in order to increase theinsulation distance along the axial direction.

Such an interphase insulation member 170 abuts on the first movementrestriction surface 231 or the second movement restriction surface 241that is formed in the inner wall part 220 of the first assembly 200,when inserted, for example, from the second assembly 300 side. At thistime, as shown in FIG. 18 , the interphase insulation member 170protrudes from the second assembly 300 to the side opposite to thestator core 100 along the axial direction.

In this case, the insulation distance can be increased along the axialdirection by the protruding length of the interphase insulation member170 protruding from the second assembly 300 to the side opposite to thestator core 100 along the axial direction.

If the interphase insulation member 170 protrudes from the secondassembly 300 to the side opposite to the stator core 100 along the axialdirection, the interphase insulation member 170 does not abut on thethird movement restriction surface 331 or the fourth movementrestriction surface 341 that is formed in the inner wall part 320 of thesecond assembly 300. Therefore, the interphase insulation member 170 maymove to the second side in the axial direction.

In this embodiment, movement of the interphase insulation member 170 tothe second side in the axial direction is restricted by the cover 400being mounted onto the second assembly 300.

As shown in FIGS. 14, 15 and 16 , the cover 400 has an outer peripheralwall 410, an inner peripheral wall 420 and a bottom wall 430.

The outer peripheral wall 410 has an outer peripheral surface and aninner peripheral surface and extends in the circumferential directionand the axial direction.

The inner peripheral wall 420 is arranged radially inside of the outerperipheral wall 410 and has an outer peripheral surface and an innerperipheral surface and extends in the circumferential direction and theaxial direction.

The bottom wall 430 extends in the circumferential direction and theradial direction between the outer peripheral wall 410 and the innerperipheral wall 420.

The outer peripheral wall 410, the inner peripheral wall 420 and thebottom wall 430 define a recess 400 a extending in the circumferentialdirection.

The cover 400 has at least one communication hole for communicationbetween the inside and the outside. In this embodiment, communicationholes 431 are formed in the bottom wall 430. Provision of thecommunication holes 431 suppresses a temperature rise within the cover400.

Further, a mounting mechanism for mounting the cover 400 onto the secondassembly 300 is provided.

In this embodiment, the mounting mechanism has at least one set of anengagement piece 440 and an engagement recess 360 configured to beengaged with the engagement piece.

As shown in FIG. 4 , the engagement recess 360 is formed in the innerperipheral surface 311 of the outer wall part 310 of the second assembly300. The engagement recess 360 is defined by an engagement recessforming face 361 (FIG. 17 ). As shown in FIG. 16 , the engagement piece440 is formed on the back side of the bottom wall 430 (within the recess400 a) of the cover 400. The engagement piece 440 has a claw 441configured to be engaged with the engagement recess 360. The claw 441has a locking face 441 a configured to be locked to the engagementrecess forming face 361 that defines the engagement recess 360.

In this embodiment, a plurality of engagement recesses 360 are formedalong the circumferential direction in the inner peripheral surface 311of the outer wall part 310 of the second assembly 300. Further, aplurality of engagement pieces 440 are formed along the circumferentialdirection within the recess 400 a of the cover 400.

In order to mount the cover 400 onto the second assembly 300, the outerperipheral wall 410 of the cover 400 is placed on the outside of theouter wall part 310 of the second assembly 300 and then the cover 400 ismoved to the first side in the axial direction. At this time, the claw441 of the engagement piece 440 is inserted into the engagement recess360 from the inside in the radial direction by elastic force of theengagement piece 440. Thus, as shown in FIG. 17 , the locking face 441 aof the claw 441 is locked to the engagement recess forming face 361.

The outer peripheral wall 410 of the cover 400 covers the crossover wireguided along the outer peripheral surface 312 of the outer wall part 310when arranged on the outside of the outer wall part 310 of the secondassembly 300. This prevents the crossover wire from coming into contactwith other parts and thus enhances the electrical insulating properties.

The tension of the crossover wire guided along the outer peripheralsurface 312 of the outer wall part 310 acts to contract (reduce) thediameter of the outer wall part 310. On the other hand, a force ofengagement between the engagement piece 440 (the locking face 441 a ofthe claw 441) and the engagement recess 360 (the engagement recessforming face 361) acts to expand the diameter of the outer wall part310. Therefore, the tension of the crossover wire guided along the outerperipheral surface 312 of the outer wall part 310 can be enhanced(increased) without reducing the strength of the outer wall part 310.

The shape of the bottom wall 430 can be appropriately selected. In thisembodiment, the bottom wall 430 is configured such that, with the cover400 mounted onto the second assembly 300, when viewed from the firstside in the axial direction (the side opposite to the stator core 100),part of the winding part 131 is covered by the bottom wall 430 on theoutside of the inner peripheral wall 420 in the radial direction, whileanother part of the winding part 131 is exposed on the inside of theinner peripheral wall 420 in the radial direction. This preventsinterference of a jig (with the winding part 131) when the stator 10 isassembled to (with) a compressor 900, as shown in FIG. 24 . Further,this configuration enhances the effect of cooling the winding part 131.

Movement of the interphase insulation member 170 to the second side inthe axial direction is restricted by the cover 400 being mounted ontothe second assembly 300.

Where the interphase insulation member 170 to be used has a length notprotruding from the first assembly 200 or the second assembly 300 to theside opposite to the stator core 100, the cover 400 for restrictingmovement of the interphase insulation member 170 can be omitted.

Even in such a case, however, if the cover 400 is mounted onto thesecond assembly 300, the crossover wire guided along the outerperipheral surface 312 of the outer wall part 310 of the second assembly300 can be prevented from coming into contact with other parts.

Where the stator winding 130 is formed by star-connected first to thirdphases (e.g., U-, V- and W-phases) of stator winding portions, ends ofthe stator winding portions of the first to third phases on the neutralpoint connection side are connected in common to the neutral point andjoined, for example, by welding.

In this case, the common connection part (neutral point) is covered withan insulation member and guided along the circumferential directionwithin the recess 200 a of the first assembly 200.

Even if the common connection part is covered with an insulation member,however, other parts such as a lead wire may be damaged due to contactwith the common connection part.

In this embodiment, damage to other parts due to contact with the commonconnection part is prevented by a particular arrangement of the commonconnection part covered with an insulation member.

One example of arrangement of the common connection part is shown inFIG. 20 .

The stator winding portions of U-, V- and W-phases respectively have thepower supply side lead wires that are connected to a power supply andthe neutral point side lead wires that are connected to a neutral point.In FIG. 20 , only the neutral point side lead wires 130Ub, 130Vb, 130Wbof the stator winding portions of U-, V- and W-phases are shown.

The power supply side lead wires are covered with an insulation memberand guided along the circumferential direction within the recess 200 aof the first assembly 200. In FIG. 20 , only insulation members 160U,160V covering the power supply side lead wires of U- and V-phases areshown, and an insulation member covering the power supply side leadwires of W-phase is not shown (is hidden). An insulation tube havingelectrical insulating properties, for example, is used as the insulationmembers 160U, 160V.

Further, the neutral point side lead wires 130Ub, 130Vb, 130Wb areconnected in common and joined, for example, by thermal welding, andthereby form the common connection part (neutral point). The commonconnection part is covered with an insulation member 140.

As shown in FIGS. 19A and 19B, for example, the insulation member 140 isformed of a resin film 150 having electrical insulating properties.

First, as shown in FIG. 19A, the resin film 150 is rolled into a tubularform.

Then, parts of the resin film shown by arrows 151, 152 are joined, forexample, by ultrasonic welding. Thus, as shown in FIG. 19B, theinsulation member 140 is formed by a tubular body having a joint part141 on one end and an opening 140 a on the other end.

The common connection part is inserted into the insulation member 140via the opening 140 a.

Further, the common connection part covered with the insulation member140 is mounted on at least one of the insulation members covering thepower supply side lead wires, for example, on the insulation members160U, 160V as shown in FIG. 20 . In this state, the insulation members140, 160 are bound together with the binding string 180. At this time,the thin parts 215 and the communication holes 216, which are describedabove and shown in FIG. 13 , are utilized to prevent the binding string180 from projecting outward from the outer peripheral surface 212 of theouter wall part 210.

Another example of arrangement of the neutral point side lead wires isshown in FIG. 21 . In FIG. 21 , the neutral point side lead wires 130Ub,130Vb, 130Wb are connected in common and joined and thereby form thecommon connection part. The common connection part is covered with aninsulation member 140.

The common connection part covered with the insulation member 140 isarranged between the winding parts respectively wound around the teeth112 adjacent in the circumferential direction.

Where the interphase insulation member 170 is arranged between thewinding parts respectively wound around the teeth 112 adjacent in thecircumferential direction, the common connection part may be arranged inthe interphase insulation member 170 (between the first central part 172and the second central part 173).

In the motor according to the first embodiment, processing of the endparts of the stator winding portions is performed on the first assembly200 side, and wire processing of the crossover wires is performed on thesecond assembly 300 side, but this is not limitative.

A motor according to a second embodiment of the present disclosure isshown in FIGS. 22 and 23 .

A stator 20 that forms the motor of the second embodiment includes astator core 500, first and second assemblies 600 and 700 respectivelyarranged on the first and second sides of the stator core 500 in theaxial direction, and a cover 800 mounted on the first assembly 600.

In this embodiment, processing of the end parts of the stator windingportions and wiring processing of the crossover wires are performed onthe first assembly 600 side. Specifically, notches 616A, 616B, 616C areformed by notching an outer wall part 610 of the first assembly 600, andguide grooves 615A, 615B, 615C are formed in an outer peripheral surfaceof the outer wall part 610.

These processings are performed in the same manner as in the firstembodiment, and therefore not described.

Next, a compressor 900 according to one embodiment of the presentdisclosure is described with reference to FIG. 24 .

The compressor 900 includes a motor 50 and a compression mechanism 60.The compressor 900 of this embodiment uses the above-described motor 50of the first embodiment of this disclosure. The motor 50 and thecompression mechanism 60 are disposed within a closed container 910. Asuction port (pipe) 911 and a discharge port (pipe) 912 are provided inthe closed container 910.

The motor 50 includes the above-mentioned stator 10 and a rotor 30. Therotor 30 includes a rotating shaft 40.

The compressor mechanism 60 compresses refrigerant sucked through thesuction port 911 and discharges it from the discharge port 912, byrotation of the rotating shaft 40.

Known compression mechanism of various configurations can be used as thecompression mechanism 60. The motor 50 and the compression mechanism 60can be arranged either along the vertical direction or along thehorizontal direction.

The motor having the stator 20 according to the second embodiment canalso be used as the motor for driving the compression mechanism 60.

The present disclosure is not limited to the structures described in theabove embodiment, but rather, may be added to, changed, replaced withalternatives or otherwise modified.

The first and second electrical insulator assemblies are not limited tothose described in this embodiment. For example, the material and shapeof the first and second electrical insulator assemblies may beappropriately changed. The inner wall projection may be formed on one orboth of the inner wall parts of the first and second electricalinsulator assemblies. The notches and the guide grooves may be formed inboth of the outer wall parts of the first and second electricalinsulator assemblies, and may just be formed in at least one of theouter wall parts of the first and second electrical insulatorassemblies.

The first to fourth inner wall projections are provided, but the numberof the inner wall projections may be appropriately changed. For example,only the first and second inner wall projections or only the third andfourth inner wall projections may be provided, or the inner wallprojections may be omitted

The slot insulation member is not limited to that described in thisembodiment. For example, the material and shape of the slot insulationmember may be appropriately changed. The interphase insulation member isnot limited to that described in this embodiment.

For example, the material and shape of the interphase insulation membermay be appropriately changed.

The cover is not limited to that described in this embodiment. Forexample, the material and shape of the cover may be appropriatelychanged. The cover may be omitted.

Any of the technical features of the above embodiment may be usedseparately or in combination of appropriately selected ones.

The present disclosure may also be configured as a stator, a motorhaving a stator, or a compressor using a motor as a driving source.

DESCRIPTION OF THE REFERENCE NUMERALS

-   10, 20: stator-   30: rotor-   40: rotating shaft-   41: bearing-   50: motor-   60: compression mechanism-   100, 500: stator core-   100 a, 500 a: stator core inner space-   100A, 100B, 500A, 500B: stator core end surface-   111: yoke-   111 a: yoke inner peripheral surface-   112: tooth-   113: tooth base part-   113 a, 113 b: tooth base part side surface (tooth side surface)-   114: tooth tip part-   114A, 114B: tooth projection-   114 a: tooth tip part inner peripheral surface-   114 b, 114 c: tooth tip part outer peripheral surface-   120: slot insulation member-   120 a to 120 d: edge-   120A to 120D: folding line-   121, 125: end part-   122, 124: intermediate part-   123: central part-   130: stator winding-   130Ub, 130Vb, 130Wb: the other end part (neutral point side end    part) of stator winding portion-   131: winding part-   132: lead wire-   132 a: winding start wire-   132 b: winding end wire-   140: insulation member-   140 a: opening-   141: joint part-   150: resin film-   160U, 160V: insulation member-   170: interphase insulation member-   170 a to 170 d: edge-   170A to 170C: folding line-   171, 174: end part-   172, 173: central part-   180: binding string-   200, 300, 600, 700: electrical insulator assembly-   200 a, 300 a: recess-   210, 310, 610: outer wall part-   211, 311: inner peripheral surface-   212, 312: outer peripheral surface-   212 m, 221 m, 312 m, 321 m: inclined surface-   213: groove-   213 a, 213 b: side wall-   213 c: bottom wall-   215: thin part-   216: communication hole-   220, 320, 620: inner wall part-   221, 321: inner peripheral surface-   222, 322: outer peripheral surface-   230, 240, 330, 340: flange-   231, 241, 331, 341: movement restriction surface (axial movement    restriction surface)-   232, 242, 332, 342: outer peripheral surface-   233, 243, 333, 343: inner wall projection-   233 a, 243 a, 333 a, 343 a: end surface (axial movement restriction    surface)-   233 b, 243 b, 333 b, 343 b: side surface-   230 a, 240 a, 330 a, 340 a: recess-   230 b, 240 b, 330 b, 340 b: recess-   250, 350: connection part-   250A, 350A: electrical insulator assembly end surface-   251, 351: top surface-   252, 253, 352, 353: side surface-   254, 255, 354, 355: groove-   254 a, 354 a: projection-   256, 257, 356, 357: stepped surface-   315A to 315C, 615A to 615C: guide groove-   316, 316A to 316C, 616A to 616C: notch-   316 a, 316 b: side wall-   316 c: bottom wall-   360, 660: engagement recess-   361: engagement recess forming face (engagement face)-   400, 800: cover-   400 a: recess-   410: outer peripheral wall-   420: inner peripheral wall-   430: bottom wall-   431: communication hole-   440: engagement piece-   441: claw-   441 a: locking face-   900: compressor-   910: closed container-   911: suction port-   912: discharge port

What is claimed is:
 1. A motor comprising: a stator; and a rotorrotatable relative to the stator; the stator having a stator core, aplurality of electrical insulator assemblies and a stator winding, thestator core having a yoke extending annularly around an axis of thestator core and a plurality of teeth extending radially inward from theyoke, the electrical insulator assemblies including a first electricalinsulator assembly arranged on a first stator core end surface on afirst side of the stator core in an axial direction and a secondelectrical insulator assembly arranged on a second stator core endsurface on a second side of the stator core in the axial direction, eachof the first electrical insulator assembly and the second electricalinsulator assembly having an outer wall part extending in acircumferential direction and facing the yoke, and a plurality ofextending parts extending radially inward from the outer wall part eachfacing the tooth, the stator winding having a plurality of windingphases, each of the winding phases having a plurality of windingportions, each of the winding portions having a winding part woundaround the tooth of the stator core and the extending parts of the firstelectrical insulator assembly and the second electrical insulatorassembly, and a pair of extensions continuously extending from a firstend and a second end of the winding part, respectively, wherein theouter wall part has a prescribed radial thickness and includes aplurality of notches extending radially therethrough and configured toguide the extensions between an inner peripheral surface and an outerperipheral surface of the outer wall part, and the outer peripheralsurface of the outer wall part adjacent to the notches is configuredsuch that the radial thickness of the outer wall part graduallydecreases toward the notch along a circumferential direction of theyoke.
 2. The motor as defined in claim 1, wherein the stator has a coverthat is removably mounted onto at least one of the first electricalinsulator assembly and the second electrical insulator assembly, thecover has an outer peripheral wall that extends in the circumferentialdirection and is arranged outside of the outer peripheral surface of theouter wall part, an inner peripheral wall that extends in thecircumferential direction and faces the inner peripheral surface of theouter peripheral wall in the radial direction, and a bottom wall thatconnects the outer peripheral wall and the inner peripheral wall, andpart of the winding part is covered by the bottom wall on the outside ofthe inner peripheral wall in the radial direction, while another part ofthe winding part is exposed on the inside of the inner peripheral wallin the radial direction.
 3. The motor as defined in claim 2, wherein thebottom wall has a through hole formed therethrough in the axialdirection.
 4. The motor as defined in claim 2, wherein an interphaseinsulation member is provided between the winding parts of differentwinding phases adjacent to each other, within a slot defined between theteeth adjacent to each other, and movement of the interphase insulationmember toward the at least one electrical insulator assembly in theaxial direction is restricted by the inner peripheral wall of the cover.5. The motor as defined in claim 1, wherein the winding part is woundfrom the outer wall side of one of the first electrical insulatorassembly and the second electrical insulator assembly, one of the pairof the extensions is a winding start wire that extends continuously tothe winding part on the outer wall side of the one electrical insulatorassembly, at least one of the winding start wires is covered with aninsulation tube, the at least one winding start wire and the insulationtube are drawn out from the inner peripheral surface side to the outerperipheral surface side of the outer wall part via one of the notchesand drawn back from the outer peripheral surface side to the innerperipheral surface side of the outer wall part via another one of thenotches, and the drawn-back winding start wire and the insulation tubeoverlap with the winding part in the axial direction.
 6. The motor asdefined in claim 5, wherein the stator winding is formed by a firstwinding phase to a third winding phase which are star-connected, aneutral point of the first winding phase to the third winding phase iscovered with an insulation member, and the insulation member is mountedto the insulation tube.
 7. The motor as defined in claim 5, wherein thestator winding is formed by a first winding phase to a third windingphase which are star-connected, a neutral point of the first windingphase to the third winding phase is covered with an insulation member,and the insulation member is arranged between the winding portionsadjacent to each other.
 8. A compressor having a compression mechanismfor compressing refrigerant and a motor for driving the compressionmechanism, wherein the motor comprises the motor according to claim 1.